How hard is it to get a crank-arm for one side that's longer than the other? What would it cost? Can I keep my current chainset/crank and just swap out the left-side crankarm? Can you even buy one crankarm, or do I have to buy an entire chainset?

(And just out of curiosity, how many here have diff. length crank arms?)

Your bike shop can order individual crankarms, but they are not cheap (usually more than half the price of a complete crankset).

Try e-Bay, sometimes see single crank arms for sale there.

Why do you want different length cranks? I know one leg is longer than the other, but I didn't think it would affect pedalling circimfrance much. Just toyed around with shimming cleats. Curious to know what makes people desire this setup?

+1.

What Crankset are you running?

If your leg length discrepancy is between your foot and knee, you need a cleat shim. If it's between your knee and hip, you want a different crank length. Adding shims to solve the latter problem will only make the problem worse.

Why would you want to do that? I don't understand how it would help anything.

???

jw

Hey, thanks. I was just considering asking why anyone would get asymmetrical cranks. Question answered!

ou could try powercranks adjustable - they're expensive but "adjustable length crank which easily changes from 85mm to 220mm" and anything in between

One leg is shorter than the other in the thigh, not the shin (by quite a bit).

220?

I bet Indurain would be all over those.

Wouldn't that just make you ride uncontrollably in circles?

Talk about pedal strike, owwwwwwwwwwwwwwwwww

To get wwhat you need, you may want to determine your crank/BB type, crank length you have and length you need.

Post in "For Trade" thread here (and potentially Classic & Vintage if you ride an older bike) and say something like the following, substituting appropriately:

"For trade my 175mm (square taper/Octalink/ISIS) left crank arm for your similar left crank arm with a length of 170."

Or, especially if you have a square taper BB, scour thrift stores and flea markets for a bike with the appropriate length cranks. It might be cheaper than buying a new crank arm. Especially if you aren't too concerned with an exact match of the appearance and model.

For the actual switch, a crank puller is the only special tool needed (and I hear there are a few cranks with self-extractors) it is a pretty straight forward operation, and a bike shop would do it for about what it would cost you to buy a crank puller if you aren't the DIY type.

They might not be that much more expensive if you end up having to buy two whole cranksets to get what you're after. Also, considering that you can probably get a lot closer to what you need than you can with stock crank lengths, the Powercranks are probably the best solution.

Whether the OP wants to spring for a set is another story though.

At $1,000 for the adjustable power cranks ($1200 if you want a lockout to be able to use them like normal cranks) it would be more affordable to have a machinist custom fabricate a left side crank of the proper length... assuming the proper length is known.

If it is not known, then an adjustable crank would be the only way to ensure that buying one item gives the solution... But at the same cost as several attempts at cheaper solutions (unless the OP is using high end equipment).

The OP could shop around and buy a full middle range drivetrain group with a shorter crank length just to use the left crank and throw the rest away and still be less expensive than the powercrank. If the OP does this, please tell me where you are throwing the remaining components.

If he is riding a Trek 1000, it would be cheaper to buy another Trek 1000, get the cranks swapped by the LBS (for little or no cost) and then pull off the left crank for his current bike, and throw the rest of the bike away...

If there is no good information on how much shorter the crank needs to be, I would just go for buying a couple of left side cranks instead of full groups or bikes. If 168.2 is the proper size, then custom work or the adjustable cranks are the solutions that would allow that.

If someone is looking for a different length crank, I suggest that they just buy one... However, if someone also wants the features of the Powercrank, or adjustable length then my whole argument collapses... and I suggest that you buy one.

donrhummy, What crank components are on your bike now?

Holy...!

I thought they were like $600 max. Sheesh!

yeah I know - when you first see the price it's "they'ze HOW MUCH"

Wow, these prices are ridiculous. it doesn't cost that much to buy shimano's complete chainset/crank. I currently have bontrager cranks on the bike.

I went to my LBS and ordered a left crank arm for $10. It was chrome plated and not marked shimano. It was for my beater bike rebuild.

Nfields

Just in case you're interested, there's some guy selling a set of ultegra cranks, right 172.5 and left 175 on ebay. Seperate auctions starting at $5 each. I was tempted but I really don't know if my length is in the shin or thigh, and I really don't have a problem with matched cranks anyway as long as the seat is set correctly.

Human bodies are not precision machines and it is common to have slight differences in leg length. Having a longer crank one side is not going to help because this will make the one leg go higher at the top of the pedal stoke.

Unless the difference is so extreme that you need a build-up shoe on one foot to walk normally, (In which case you may need a build up cycling shoe.) don’t even worry about it. At the bottom of each pedal stroke on the short side your toe will point down a little further than the other side.

Left crankarms are easily available and generally not too expensive. There are several that fall in the $20.00 range. Don't expect them to perfectly match what you have on the drive side.

There's over an inch in difference between the two legs. I'm still not 100% certain whether the longer crank arm or something on the bottom of the shoe is best, but the crank arm diff. does make some sense to me. The problem is that if the crank arms are the same length, when the longer leg is perfectly angled at the bottom of the pedal stroke, the shorter leg is not. There's no way to get them both set up properly (pedal under knee, leg slightly bent at bottom) if both cranks are the same length.